In many applications within different fields, for example in the automotive or industrial field, electronic control units (ECUs) are used to implement many different functions. Different ECUs inside one application often need to exchange data. In addition to communication within an on-board system, communication with external components is also required for many applications.
In order to communicate, the ECUs should be interconnected. In this way they form networks. Within these networks, mainly serial bus systems are used for communication. Different serial bus systems are known today, such as CAN (Controller Area Network), LIN (Local Interconnect Network), FlexRay or MOST (Media Oriented Systems Transport).
The ECUs that communicate over the bus system generally include a transceiver for sending and receiving of data. Switching operations performed within the transceivers, however, can cause electromagnetic emissions. Such disturbing influences should be kept as low as possible, as they may induce unwanted effects in applications, especially in automotive applications which generally include highly integrated modules.
It is known to damp these emissions with the use of inductors. Often, in this context, such inductors are referred to as chokes or common mode chokes. These inductors, however, need to have a certain inductance, and therefore size, to achieve the desired filter effect. This makes the inductors too big to integrate them into the transceivers. They therefore need to be provided as external components, which results in additional costs for the ECU manufacturers.
Therefore, a solution is needed, which reduces the electromagnetic emissions within bus networks at reduced costs.